Sentry Sprinklers Model GD-3000 and TD-3000 are ductile iron Butterfly Valves that are bi-directional and suited for vertical and horizontal installation. The valve is the indicating type designed and listed for use in fire protection systems with a built in tamper switch suitable for indoor and outdoor use. The switch box and valve body are anti-corrosion with 10 mil (250μ) of fusion-bonded epoxy (FBE) coating. All other components are made of corrosive resistance materials.